Acetone vs alcohol for degreasing.

admin

We have a big debate going on in the shop - should we change from degreasing with acetone to alcohol.  A bit of research (GOOGLE) found that denatured alcohol would be better because of the zero water content, but how do acetone and alcohol compare, apart from price.  And should we be considering anything else?  We are mainly welding nickel and the welds looks the same for both.Would appreciate any insight.Poe
Reply:Originally Posted by PoeWe have a big debate going on in the shop - should we change from degreasing with acetone to alcohol.
Reply:I can't tell you which is best. I have used both and can't tell any difference. I can say I would be less afraid to get alcohol on my hands, and the alcohol is one of the best electronic cleansers there is. I have never considered the price as I don't really need it that much. Most of my welding is on rusty stuff.
Reply:Unless you believe there is any silcone on the surface of what your cleaning you should be able to get bye with alcohol. I prefer acetone because I know it gets most everything and evaporates quickly. But your right about the price difference.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:What do you mean "zero water content" for denatured alcohol versus acetone?Plain acetone really doesn't have water in it.Alcohol absorbs moisture from the air, so even if it didn't have any water in it to start with (100% alcohol), as soon as it is exposed to the air it will have -some- water in it.And different denaturing additives may be added to the main ethanol base to make the alcohol into "denatured alcohol".  Countries may specify what may be used to denature the ethanol, or 'formulas' may change, etc, etc.  And what formerly worked fine for you may suddenly not work, because the denaturing agent changed in the mix.Also, there may be environmental issues for industrial use of various solvents that you should check into (if you already haven't).YMMV, etc.  The best laid schemes ... Gang oft agley ...
Reply:Sorry to be inaccurate.  I meant denatured alcohol contains no water when compared to other alcohols, eg rubbing.
Reply:Porbably the best reason to use acetone is that it leaves no residue when it evaporates.  Denatured alcohol has a small amout of peproleum oil added in the denaturing process.  If your work does not require WC x-ray then it probably does not make much difference.
Reply:The shop I was at used break cleaner it was pretty nasty.
Reply:Ethanol is a very polar molecule so is not as good a solvent as many straight alkanes or aromatic solvents, particularly for hydrocarbons like automotive oils and greases. The government has, for it,  dozens of approved denaturants including gasoline, diesel fuel, methanol, fusil oil, pyridine, etc. Methanol is often both cheaper and a better solvent than ethanol but for most of the contaminants I run into during shop work, acetone is far superior than either alcohols.
Reply:I am gonna butt in here.  Haven't really said much, but lurked in the shadows for some time.  One of the things to look into is what residue is left after the product is used.  As being a automotive tech for 20 years, have run into a lot of different brake cleaners.  How I was taught for brake clean residue will also hold true for most cleaning chemicals.  With any chemical, spray or wipe it onto a clean piece of glass.  Once it has dries, look at the glass.  One of the best windows to use is the kitchen window, cause if it is hazy, you sure hear about it from the wife.  I know with brake clean that the better ones will not give any haze.  You sure know when you have a lower grade of chemical when you inspect it after.  As far as I can figure this should hold true also for the chemicals mentioned.  There are tones of product all under the same name, but the quality is different for each manufacture.  Then there is the unseen differences between different chemicals. This test is for chemicals that vaporize fast. HTHGlennMiller Econotwin HF with Weldcraft TIG
Reply:Pour some denatured alcohol in a (clear) glass, pour some oil in there too, shake it, swirl it, do whatever you want to do to get it to blend then let it set over night and check the mix in the morning. Do the same with some acetone and any other of your favorites you may want to chose from at the same time. Everybody can view the results and come to a consensus from there. Plunk in some costs, risk factors and other pros and cons.  Maybe get in a bit of friendly debating while you're at it.
Reply:Definitely go with the AcetoneCheers
Reply:I hadn't originally noticed your mention of welding Nickel. [Only slightly off topic, but maybe useful still?]:Nickel will adsorb small amounts of sulfur,phosphorus, lead, cadmium, and others I've forgotten. These contaminants affect the weld strength so need to be prevented; common sources are paint and some lubricants, particularly greases which use metallic-based soaps. Also grease containing MoS2. You might test some of these as Sandy suggested, just out of curiosity even if they couldn't be a problem there.
Reply:Acetone smells more fun!!!And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Thanks for the advice - so I took some it and tested the welds.  We degreased 5 pairs of coupons with some 99% alcohol we had hanging around and 5 pairs of coupons with acetone.  We have peel tester sitting in the shop for one of our customers QA tests, so we did the resistance welds on these coupons and....................................... the alcohol degreased parts had about 70% of the strength of the acetoned bits.  All a bit crude I know, but I am sticking with the more expensive acetone.Poe
Reply:Acetone is the best.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:the alcohol degreased parts had about 70% of the strength of the acetoned bits. All a bit crude I know, but